Comparison of antiarrhythmic drug therapy and radiofrequency catheter ablation in patients with paroxysmal atrial fibrillation: a randomized controlled trial

Catheter ablation vs. thoracoscopic surgical ablation in long-standing persistent atrial fibrillation: CASA-AF randomized controlled trial

AIMS

Long-standing persistent atrial fibrillation (LSPAF) is challenging to treat with suboptimal catheter ablation (CA) outcomes. Thoracoscopic surgical ablation (SA) has shown promising efficacy in atrial fibrillation (AF). This multicentre randomized controlled trial tested whether SA was superior to CA as the first interventional strategy in de novo LSPAF.

METHODS AND RESULTS

We randomized 120 LSPAF patients to SA or CA. All patients underwent predetermined lesion sets and implantable loop recorder insertion. Primary outcome was single procedure freedom from AF/atrial tachycardia (AT) ≥30 s without anti-arrhythmic drugs at 12 months. Secondary outcomes included clinical success (≥75% reduction in AF/AT burden); procedure-related serious adverse events; changes in patients' symptoms and quality-of-life scores; and cost-effectiveness. At 12 months, freedom from AF/AT was recorded in 26% (14/54) of patients in SA vs. 28% (17/60) in the CA group [OR 1.128, 95% CI (0.46-2.83), P = 0.83]. Reduction in AF/AT burden ≥75% was recorded in 67% (36/54) vs. 77% (46/60) [OR 1.13, 95% CI (0.67-4.08), P = 0.3] in SA and CA groups, respectively. Procedure-related serious adverse events within 30 days of intervention were reported in 15% (8/55) of patients in SA vs. 10% (6/60) in CA, P = 0.46. One death was reported after SA. Improvements in AF symptoms were greater following CA. Over 12 months, SA was more expensive and provided fewer quality-adjusted life-years (QALYs) compared with CA (0.78 vs. 0.85, P = 0.02).

CONCLUSION

Single procedure thoracoscopic SA is not superior to CA in treating LSPAF. Catheter ablation provided greater improvements in symptoms and accrued significantly more QALYs during follow-up than SA.

CLINICAL TRIAL REGISTRATION

ISRCTN18250790 and ClinicalTrials.gov: NCT02755688.

Pulsed field ablation selectively spares the oesophagus during pulmonary vein isolation for atrial fibrillation

Aims

Extra-atrial injury can cause complications after catheter ablation for atrial fibrillation (AF). Pulsed field ablation (PFA) has generated preclinical data suggesting that it selectively targets the myocardium. We sought to characterize extra-atrial injuries after pulmonary vein isolation (PVI) between PFA and thermal ablation methods.

Methods and results

Cardiac magnetic resonance (CMR) imaging was performed before, acutely (<3 h) and 3 months post-ablation in 41 paroxysmal AF patients undergoing PVI with PFA (N = 18, Farapulse) or thermal methods (N = 23, 16 radiofrequency, 7 cryoballoon). Oesophageal and aortic injuries were assessed by using late gadolinium-enhanced (LGE) imaging. Phrenic nerve injuries were assessed from diaphragmatic motion on intra-procedural fluoroscopy. Baseline CMR showed no abnormality on the oesophagus or aorta. During ablation procedures, no patient showed phrenic palsy. Acutely, thermal methods induced high rates of oesophageal lesions (43%), all observed in patients showing direct contact between the oesophagus and the ablation sites. In contrast, oesophageal lesions were observed in no patient ablated with PFA (0%, P < 0.001 vs. thermal methods), despite similar rates of direct contact between the oesophagus and the ablation sites (P = 0.41). Acute lesions were detected on CMR on the descending aorta in 10/23 (43%) after thermal ablation, and in 6/18 (33%) after PFA (P = 0.52). CMR at 3 months showed a complete resolution of oesophageal and aortic LGE in all patients. No patient showed clinical complications.

Conclusion

PFA does not induce any signs of oesophageal injury on CMR after PVI. Due to its tissue selectivity, PFA may improve safety for catheter ablation of AF.

Rotor Drivers in Induction and Maintenance of Atrial Fibrillation

Atrial fibrillation is the most common arrhythmia in clinical practice. It is associated with an increased risk of stroke, chronic heart failure, and sudden cardiac death. Our options of restoring and maintaining sinus rhythm have a very limited effect, both in the case of antiarrhythmic and catheter treatment. Catheter ablation has proven to be a more effective approach than antiarrhythmic therapy. The success rate of the procedure reaches 70%. However, radiofrequency ablation is associated with a risk of complications, with 4.5% of patients likely to develop major complications, including tamponade (1.31%), femoral pseudoaneurysm (0.71%), and death (0.15%). Given the generally recognized dominant role of the pulmonary veins in the induction of atrial fibrillation, their electrical isolation has become the recommended tactic of the catheter approach. In the case of patients with paroxysmal form of atrial fibrillation, the success rate of the procedure reaches 87%. Unfortunately, in the case of persistent forms of atrial fibrillation, the effectiveness of the primary procedure decreases to 28% and reaches 51% with repeated interventions. In addition to the anatomically oriented isolation of the pulmonary veins, a number of strategies have been proposed to reach the secondary zones of atrial fibrillation induction. The results of recent studies on the effectiveness of strategies for ablation of rotor regions and their role in the induction and maintenance of AF may lead to the further development of catheter ablation techniques and an individual radiofrequency ablation approach in a particular patient.

Comparison of the lesion formation and safety in ex vivo porcine heart study: Using ThermoCool SmartTouch and ThermoCool SmartTouch-SF catheters

BACKGROUND

The study was performed to compare the efficacy and safety during radiofrequency ablation (RFA) using ThermoCool SmartTouch (ST) and ThermoCool SmartTouch-SF (STSF) catheters in the porcine heart.

METHODS AND RESULTS

RFA was performed on the porcine myocardium by using two irrigated ablation catheters. Three groups were divided based on the different contact forces (CFs): low contact force (LCF) (1-3 g), medium contact force (MCF) (5-10 g), and high contact force (HCF) (15-20 g). In each group, RFA was delivered at four power settings of 30, 40, 50, 60 W. At each power, RFA was applied to reach the target ablation index (AI) of 350, 450, and 500. Altogether, 360 RF lesions were created by using 72 ablation conditions. AI value was positively correlated with lesion size using ST and STSF catheters. At a fixed power, lesion dimensions significantly smaller in the LCF group, whereas did not differ between MCF and HCF groups. Furthermore, at a fixed CF, lesion dimensions increased with power set at 40 W compared with 30 W but decreased with high-power RF energy (50 and 60 W). Although the average lesion surface diameter and the maximum diameter was increased using the STSF catheter, there were no significant differences in LV between the two catheters. The steam pop provoked more frequently using ST catheter and showed a negative correlation with CF and positive correlation with high-power energy.

CONCLUSION

The STSF catheter is safer and equally effective in lesion formation compared with the ST catheter. LV was increased along with the early increase of CF and power, whereas a further increase of CF and power significantly reduces the lesion size.

Long-Term Outcomes and Improvements in Quality of Life in Patients with Atrial Fibrillation Treated with Catheter Ablation vs. Antiarrhythmic Drugs

BACKGROUND

Catheter ablation (CA) is a recognized first-line treatment for atrial fibrillation (AF) in selected patients; however, the differences between CA and antiarrhythmic drugs (AADs) in terms of long-term outcomes and quality of life (QoL) have not often been compared.

OBJECTIVES

We performed a meta-analysis of randomized controlled trials (RCTs) to compare long-term outcomes and QoL with CA and AADs in the treatment of AF.

METHODS

We searched the MEDLINE database for English-language RCTs of CA or AADs in AF from 1 January 2005 to 30 October 2019 with no other restrictions. We included studies that reported sample sizes and the long-term outcomes of interest as well as sample size, mean ± standard deviation or 95% confidence intervals (CIs) for QoL outcomes with CA and AADs.

RESULTS

We identified 20 RCTs involving 5425 participants. Compared with patients who received only AADs, patients receiving CA had a significantly decreased risk of all-cause death (relative risk [RR] 0.72; 95% CI 0.58-0.90) and cardiovascular hospitalization (RR 0.85; 95% CI 0.79-0.91). We found a significant increase in the risk of cardiac tamponade (RR 5.86; 95% CI 1.77-19.44) but no difference in the risk of heart failure, stroke or transient ischemic attack, atrial tachycardia, bleeding or hematoma, and pulmonary vein stenosis. For long-term QoL after treatment, both therapies resulted in improved scores on the Medical Outcomes Study 36-Item Short Form Survey (SF-36): weighted mean differences (WMDs) for the physical component score (PCS) were 5.89 for CA and 4.26 for AADs and for the mental component score (MCS) were 7.12 for CA and 5.06 for AADs. At the end of follow-up, groups receiving CA had significantly higher scores in both areas. The change in PCS and MCS between baseline and end of follow-up was also significantly higher in the CA groups: WMD 1.51 for change in PCS and 1.49 for change in MCS. All eight SF-36 subscale scores improved for patients receiving CA, whereas patients receiving AADs recorded no improvement in the general health and bodily pain subscales. At the end of follow-up, CA groups had significantly higher scores than AAD groups in the following subscales: physical functioning, role limitations due to physical health problems, bodily pain, general health, vitality, and role limitations due to emotional problems.

CONCLUSIONS

In the treatment of AF, CA appeared to be superior to AADs, decreasing the risk of all-cause death and cardiovascular hospitalization and improving the long-term QoL of patients with AF. CA was better tolerated and more effective than pharmacological therapy and allowed for improved QoL.

Novel model-based point scoring system for predicting stroke risk in atrial fibrillation patients: Results from a nationwide cohort study with validation

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This study used rigorous statistical method to construct the novel AF-CA-Stroke score and demonstrated that the novel stroke risk stratification tool had significantly higher discrimination abilities than conventional scores.

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This study exhibited that the status of various age stratifications and receiving AF ablation shall be considered in managing AF treatment.

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Based on the AF-CA-Stroke score, around 80–85% patients may take benefits form AF ablation procedures with lower stroke risks, and they may not be necessary to receive oral anticoagulants after receiving successful AF ablations.

Background

The stroke risk scoring system for atrial fibrillation (AF) patients can vary considerably based on patients’ status while receiving ablation. This study aimed to demonstrate a novel scoring system for stroke risk stratification based on the status of catheter ablation.

Methods

First, 787 patients with AF undergoing ablation were matched according to age, sex, and underlying diseases with the same number of patients not undergoing ablation using the propensity-score (PS)-matched cohort. Multivariate Cox model-derived coefficients were used to construct a simple point-based clinical model using the PS-matched cohort. Thereafter, the novel model (AF-CA-Stroke score) was validated in a nationwide AF cohort.

Results

The AF-CA-Stroke score was calculated based on age (point = 5), ablation status (point = 4), prior history of stroke (point = 4), chronic kidney disease (point = 2), diabetes mellitus (point = 1), and congestive heart failure (point = 1). Risk function to predict the 1-, 5-, 10-year absolute stroke risks was reported. The estimated area under the receive operating characteristic curve of the AF-CA-Stroke score in the PS-matched cohort was 0.845 (95% confidence interval: 0.824–0.865) to predict long-term stroke. A validation study showed that discrimination abilities in the AF-CA-Stroke scores were significantly higher than those in the CHADS₂/CHA₂DS_2-VASc scores. The best cut-off value of the AF-CA-Stroke score to predict future strokes was ≥ 5.

Conclusions

This novel model-based point scoring system effectively identifies stroke risk using clinical factors and AF ablation status of patients with AF. Various age stratifications and AF ablation should be considered in AF management.

Assessment of the relationship between semaphorin4D level and recurrence after catheter ablation in paroxysmal atrial fibrillation

OBJECTIVE

Semaphorin4D (Sema4D), a novel integral membrane glycoprotein, plays a role in atherosclerosis, angiogenesis and chronic inflammation. Elevated levels of sema4D were presented in myocardial infarction, heart failure and atrial fibrillation. Aim of the study was to investigate the relation between sema4D and recurrence after catheter ablation (CA) in paroxysmal AF.

METHODS

The present study included 161 paroxysmal AF patients (PAF) (101 patients undergone CA) and 60 healthy subjects. Serum levels of sema4D were measured and study participants were followed-up for 3 months and 1 year since CA in terms of recurrence respectively.

RESULTS

Sema4D levels were significantly elevated in the recurrent group compared to the non-recurrent PAF patients (p < 0.001). Sema4D was importantly positively correlated with both left atrial volume index (r = 0.51, p < 0.013) and high sensitive C-reactive protein (r = 0.38), p < 0.011). In multivariate analysis, sema4D [odds ratio (OR) = 1.23, 95% CI 1.11-1.42; p < 0.001] and left atrial diameter (OR = 1.13, 95% CI 1.02-1.23; p = 0.012) were found to be significant independent risk parameters for recurrence.

CONCLUSIONS

Sema4D is a novel biomarker that may help to identify individuals with recurrence after CA procedure in long term period in PAF.

Pulmonary Vein Isolation With Ablation Index via Single Transseptal Crossing: Critical Role of Carina Isolation

AIM

Reconnection of the pulmonary veins (PVs) is the most common reason for the recurrence of atrial fibrillation (AF). The ablation index is a marker of ablation lesion quality that achieves high percentages of first-pass isolation and improved AF ablation results. Most operators use a double transseptal approach with confirmation of PV isolation with a circular mapping catheter. In the present study we aimed to show that an ablation index-guided procedure using a single transseptal approach and ablation catheter only would achieve adequate PV isolation while demonstrating the critical role of the carina in PV isolation.

METHOD

Sixty-six (66) consecutive patients with paroxysmal AF were included. Thirty-four (34) patients underwent wide antral circumferential ablation (WACA-only) and 32 underwent WACA+ (WACA + empiric carina isolation). All procedures were performed via single transseptal approach. Pulmonary vein isolation was confirmed with the use of a circular mapping catheter in both groups.

RESULTS

Compared to WACA-only, WACA+ increased the odds of PV isolation from 65% to 94% (p=0.011). In the WACA-only procedure, ablation of the carina was needed to achieve PV isolation. At the 18-month follow-up (interquartile range 15.2-20.8 months), freedom from AF was 84% for the entire cohort.

CONCLUSIONS

Our study confirmed the high success rate of PV isolation using the ablation index and showed that this can be achieved via a single transseptal crossing. Our study confirmed the role of the carina in PV isolation.

Predictors of clinical success after paroxysmal atrial fibrillation catheter ablation

INTRODUCTION

Contact force (CF) guided ablation of paroxysmal atrial fibrillation (PAF) with stable catheter-tissue contact optimizes clinical success and may increase an operator's ability to achieve pulmonary vein isolation (PVI) in a single encirclement. First pass PVI reduces procedure time but the relationship with long term clinical success is not well understood. This study evaluated patient characteristics and procedural details as predictors of 1-year clinical success after PAF ablation, including first pass isolation.

METHODS

Consecutive de novo PAF ablations were performed with a porous tip CF catheter in 2017 and 2018. All ablations used wide-area circumferential ablation, with first pass isolation captured separately for the left and right pulmonary veins (PVs). CF was held between 10 and 20 g and the catheter was moved every 10-20 s. Radiofrequency energy was set at 40-45 W throughout the atrium. Patient characteristics and procedural details were tested for association with clinical success, defined as freedom from recurrent atrial tachyarrhythmia through 1 year.

RESULTS

A total of 404 patients were included in the study. Clinical success at 1 year was 86.6%. Achieving first pass isolation on at least one ipsilateral PV pair was the most significant predictor of clinical success (p = .0126). After controlling for first pass isolation, only recurrence within the 90-day blanking period was independently predictive (p = .0015). First pass isolation was not associated with early recurrence (p = .2454).

CONCLUSION

In a real-world setting, first pass isolation was highly predictive of 12-month clinical success after CF-guided ablation in a PAF population.

The RACE to the EAST. In pursuit of rhythm control therapy for atrial fibrillation-a dedication to Harry Crijns

The RACE trial was one of the first landmark trials to establish whether restoring and maintaining sinus rhythm could reduce morbidity and mortality in patients with atrial fibrillation (AF). Its neutral outcome shaped clinical decision-making for almost 20 years. However, there were two important treatment-related factors associated with mortality of rhythm control therapy at that time: One was safety of antiarrhythmic drug therapy, and the other one withdrawal of anticoagulation after restoration of sinus rhythm. Both concerns have been overcome, and, moreover, important knowledge considering the importance of time for the treatment of AF has been gained. These insights led to the concept of the EAST-AFNET 4 trial, and after more than two decades in the pursuit of ongoing therapeutic improvement, early rhythm control therapy has demonstrated to reduce a composite of cardiovascular death, stroke, and hospitalization for worsening of HF or acute coronary syndrome, by 21% (first primary outcome, absolute reduction 1.1 per 100 patient-years). For this entire period, Harry Crijns characterized the treatment of AF patients, and contributed decisively to realizing the benefit of rhythm control therapy. It is almost easier to list the clinical trials without Harry's involvement than to list those which he co-designed and led.

Comparison of higher-power and conventional power ablation of atrial fibrillation using contact force-sensing catheters: a systematic review and meta-analysis

BACKGROUND

Contact force-sensing catheters have been widely used in catheter ablation. During the past few decades, more attention has been paid on the technique of high-power ablation. The purpose of this meta-analysis is to compare the efficacy and safety of conventional power and high power on atrial fibrillation radiofrequency ablation by contact force-sensing catheters.

METHODS

We identified studies through searching MEDLINE, Embase, the Web of Science, Scopus, and the Cochrane Library from inception up until July 2020. The primary outcomes were defined as recurrence of atrial tachyarrhythmia and complications. The secondary outcomes were acute reconnections of pulmonary veins (PVs), ablation time, and the total procedural time.

RESULTS

Four nonrandomized, observational studies (nROS) were selected involving 231 patients with high-power ablation and 239 patients with conventional power ablation. There were insignificant differences in the recurrence rate of atrial tachyarrhythmia (14.2% versus 20.5%, OR: 0.64, 95%CI: 0.39 to 1.04, Z = 1.82, P = 0.07) and clinical complications (1.7% versus 2.5%, OR: 0.72, 95%CI: 0.21 to 2.47, Z = 0.51, P = 0.61) between high-power and conventional power ablation. However, compared with conventional power group, the high-power group had fewer acute PVs reconnections (P = 0.0001), shorter in ablation time (P < 0.0001), and the total procedural time (P < 0.0001).

CONCLUSIONS

High-power ablation could not only ablate safely and efficiently but also reduce focal ablation time and total procedural time significantly.

Effect of Outcome Measures on the Apparent Efficacy of Ablation for Atrial Fibrillation: Why "Success" is an Inappropriate Term

INTRODUCTION

Different endpoint criteria, different durations of follow-up and the completeness of follow-up can dramatically affect the perceived benefits of atrial fibrillation (AF) ablation.

METHODS

We defined three endpoints for recurrence of AF post ablation in a cohort of 200 patients with symptomatic AF, refractory to antiarrhythmic drugs (AADs). A 'Strict Endpoint' where patients were considered to have a recurrence with any symptomatic or documented recurrence for ≥30 seconds with no blanking period, and off their AADs, a 'Liberal Endpoint' where only documented recurrences after the blanking period, either on or off AADs were counted, and a 'Patient-defined Outcome endpoint' which was the same as the Liberal endpoint but allowed for up to two recurrences and one repeat ablation or DCCV during follow-up. We also surveyed 50 patients on the waiting list for an AF ablation and asked them key questions regarding what they would consider to be a successful result for them.

RESULTS

Freedom from recurrence of atrial tachyarrhythmias (AT) at 5 years was 62% for the Strict Endpoint, 73% for the Liberal Endpoint, and 80% for the Patient-defined Outcome endpoint (p<0.001). Of the 50 patients surveyed awaiting AF ablation, 70% said they would still consider the procedure a success if it required one repeat ablation or one DCCV (p=0.004), and 76% would be accepting of one or two recurrences during follow-up (p<0.001).

CONCLUSION

In this study, the majority of patients still considered AF ablation a successful treatment if they had up to two recurrences of AF, one repeat procedure or one DCCV. Furthermore, a 'Patient-defined' definition of success lead to significantly different results in this AF ablation cohort when compared to conventionally used/guideline directed measures of success.

The whole term efficacy of different treatments in paroxysmal atrial fibrillation in aging: a meta-analysis of randomized controlled trials

Antiarrhythmic drug therapy (ADT) and catheter ablation (CA) are the main treatments for paroxysmal atrial fibrillation. However, the short- and long-term clinical efficacy of these treatments remains controversial. Our goal is to investigate efficacy and safety of the standardized treatment of elderly patients with paroxysmal atrial fibrillation (PAF). Eight randomized controlled trials on CA and ADT for treating PAF were included. Totally, 1336 patients were included. Studies on CA and ADT for treating PAF that were published between January 2005 and June 2020 in the Cochrane Library, PubMed and EMBASE were screened and identified. Atrial fibrillation-free rates and Short Form (SF-36) health score-related indexes were analyzed. Atrial fibrillation-free rates were similar in the CA and ADT groups [risk ratio (RR) 1.32; 95% confidence interval (CI) 0.96-1.82; P = 0.08] at 3 months. The CA group had a significantly higher atrial fibrillation-free rate at 6 months (RR 1.87; 95% CI 1.38-2.53; P < 0.001), 9 months (RR 2.38; 95% CI 1.43-3.96; P < 0.001), and 12 months (RR 2.21; 95% CI 1.28-3.84; P=0.005). However, there was no significant difference in terms of long-term efficacy at 24 months (RR 1.81; 95% CI 0.97-3.36; P = 0.06). The 12-month QOL physical and mental components (RR 2.41; 95% CI 0.89-3.93; P = 0.002) were significantly higher in CA group. The CA is more effective than ADT in the short-term prognosis. But the long-term prognosis of PAF needs to be verified via randomized controlled trials with longer follow-up durations.

Safety and chronic lesion characterization of pulsed field ablation in a Porcine model

Background

Pulsed field ablation (PFA) has been identified as an alternative to thermal‐based ablation systems for treatment of atrial fibrillation patients. The objective of this Good Laboratory Practice (GLP) study was to characterize the chronic effects and safety of overlapping lesions created by a PFA system at intracardiac locations in a porcine model.

Methods

A circular catheter with nine gold electrodes was used for overlapping low‐ or high‐dose PFA deliveries in the superior vena cava (SVC), right atrial appendage (RAA), and right superior pulmonary vein (RSPV) in six pigs. Electrical isolation was evaluated acutely and chronic lesions were assessed via necropsy and histopathology after 4‐week survival. Acute and chronic safety data were recorded peri‐ and post‐procedurally.

Results

No animal experienced ventricular arrhythmia during PFA delivery, and there was no evidence of periprocedural PFA‐related adverse events. Lesions created in all anatomies resulted in electrical isolation postprocedure. Lesions were circumferential, contiguous, and transmural, with all converting into consistent lines of chronic replacement fibrosis, regardless of trabeculated or smooth endocardial surface structure. Ablations were non‐thermally generated with only minimal post‐delivery temperature rises recorded at the electrodes. There was no evidence of extracardiac damage, stenosis, aneurysms, endocardial disruption, or thrombus.

Conclusion

PFA deliveries to the SVC, RAA, and RSPV resulted in complete circumferential replacement fibrosis at 4‐week postablation with an excellent chronic myocardial and collateral tissue safety profile. This GLP study evaluated the safety and efficacy of a dosage range in preparation for a clinical trial and characterized the non‐thermal nature of PFA.

Combination of ablation and left atrial appendage closure as "One-stop" procedure in the treatment of atrial fibrillation: Current status and future perspective

Atrial fibrillation (AF), the most common arrhythmia, is a major cause of stroke and systemic embolism. Left atrial appendage closure (LAAC) has been proved to be noninferior to traditional Vitamin K antagonists (VKAs) as well as novel oral anticoagulants (NOACs), which is becoming an important alternative to prevent stroke in non‐valvular AF. Catheter‐based AF ablation (CA) is recommended to be a standard of care in patients with AF refractory to drug therapy due to a better rhythm control and improvement of life quality than antiarrhythmic drugs. Theoretically, the one‐stop combination with LAAC and CA tends to bring more benefits in patients with AF, as it not only relieves symptoms, but also reduces the risk of stroke significantly. However, several important questions still need to be considered in the combination procedure although quite a few attempts have already been made in clinical practice. This review provides a comprehensive update on the concept, technique, perioperative management, benefits and other critical issues of the “one‐stop” procedure.

Catheter ablation or medical therapy to delay progression of atrial fibrillation: the randomized controlled atrial fibrillation progression trial (ATTEST)

AIMS

Delay of progression from paroxysmal to persistent atrial fibrillation (AF) is an important measure of long-term success of AF treatment. However, published data on the impact of catheter ablation on AF progression are limited. This study evaluates whether radiofrequency (RF) catheter ablation delays the progression of AF compared with antiarrhythmic drug (AAD) treatment using current AF management guidelines.

METHODS

This prospective, randomized, controlled, two-arm, open-label trial was conducted at 29 hospitals and medical centres across 13 countries. Patients were randomized 1 : 1 to RF ablation or AAD treatment. The primary endpoint was the rate of persistent AF/atrial tachycardia (AT) at 3 years.

RESULTS

After early study termination following slow enrolment, 255 (79%) of the planned 322 patients were enrolled (RF ablation, n = 128, AAD, n = 127); 36% of patients in the RF ablation group and 41% in the AAD group completed 3 years of follow-up. For the primary endpoint, the Kaplan-Meier estimate of the rate of persistent AF/AT at 3 years was significantly lower with RF ablation [2.4% (95% confidence interval (CI), 0.6-9.4%)] than with AAD therapy [17.5% (95% CI, 10.7-27.9%); one-sided P = 0.0009]. Patients ≥65 years were ∼4 times more likely to progress to persistent AF/AT than patients <65 years, suggesting RF ablation can delay disease progression [hazard ratio: 3.87 (95% CI, 0.88-17.00); P = 0.0727]. Primary adverse events were reported for eight patients in the RF ablation group.

CONCLUSIONS

Radiofrequency ablation is superior to guideline-directed AAD therapy in delaying the progression from paroxysmal to persistent AF.

The 4S-AF Scheme (Stroke Risk; Symptoms; Severity of Burden; Substrate): A Novel Approach to In-Depth Characterization (Rather than Classification) of Atrial Fibrillation

Atrial fibrillation (AF) is a complex condition requiring holistic management with multiple treatment decisions about optimal thromboprophylaxis, symptom control (and prevention of AF progression), and identification and management of concomitant cardiovascular risk factors and comorbidity. Sometimes the information needed for treatment decisions is incomplete, as available classifications of AF mostly address a single domain of AF (or patient)-related characteristics. The most widely used classification of AF based on AF episode duration and temporal patterns (that is, the classification to first-diagnosed, paroxysmal, persistent/long-standing persistent, and permanent AF) has contributed to a better understanding of AF prevention and treatment but its limitations and the need for a multidimensional AF classification have been recognized as more complex treatment options became available. We propose a paradigm shift from classification toward a structured characterization of AF, addressing specific domains having treatment and prognostic implications to become a standard in clinical practice, thus aiming to streamline the assessment of AF patients at all health care levels facilitating communication among physicians, treatment decision-making, and optimal risk evaluation and management of AF patients. Specifically, we propose the 4S-AF structured pathophysiology-based characterization (rather than classification) scheme that includes four AF- and patient-related domains-Stroke risk, Symptoms, Severity of AF burden, and Substrate severity-and provide a hypothetical model for the use of 4S-AF characterization scheme to aid treatment decision making concerning the management of patients with AF in clinical practice.

Reduction of mortality by catheter ablation in real-world atrial fibrillation patients with heart failure

Whether catheter ablation for atrial fibrillation (AF) improves survival and affects other outcomes in real-world heart failure (HF) patients is unclear. This study aimed to evaluate whether ablation reduces death, and other outcomes in real-world AF patients with HF. Among 834,735 patients with AF from 2006 to 2015 in the Korean National Health Insurance Service database, 3173 HF patients underwent AF ablation. Propensity score weighting was used to correct for differences between the groups. During median 54 months follow-up, the risk of all-cause death in ablated patients was less than half of that in patients with medical therapy (2.8 vs. 6.2 per 100 person-years; hazard ratio [HR] 0.42, 95% confidence interval [CI] 0.27–0.65, p < 0.001). Ablation was related with lower risk of cardiovascular death (HR 0.38, 95% CI 0.32–0.62, p < 0.001), HF admission (HR 0.39, 95% CI 0.33–0.46, p < 0.001) and stroke/systemic embolism (HR 0.44, 95% CI 0.37–0.53, p < 0.001). In subgroup analysis, the risk of all-cause death was reduced in most subgroups except in the elderly (≥ 75 years) and strictly anticoagulated patients. Ablation may be associated with reduced risk of all-cause death and cardiovascular death in real-world AF patients with HF, supporting the role of AF ablation in patients with HF.

Redefining the Standard for Atrial Fibrillation: A Patient-centric Report

A roundtable discussion with three European clinical experts in AF and one expert patient diagnosed and treated for AF was conducted in London in October 2019. The panel discussed the implications of AF for patients, current patient pathways, what treatment outcomes were relevant for patients and how the recommendations for the management of AF may change in the future, based on the outcomes of recently published and on-going clinical trials. This article summarises the discussion, and draws upon wider sources to detail best practice and optimal patient treatment pathways.

What clinical trials of ablation for atrial fibrillation tell us - and what they do not

Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia in clinical practice. Radiofrequency and cryoballoon catheter ablation are therapeutic options in addition to antiarrhythmic drug therapy for the treatment of AF. Ablation is effective at reducing recurrent atrial arrhythmias and also in the reduction of AF burden. Besides arrhythmia control, improvement in quality of life and clinical outcomes are also desirable goals with AF treatment. Randomized clinical trials have evaluated ablation in several patient populations, including symptomatic patients as first-line or second-line therapy, asymptomatic patients, and patients with heart failure. These trials clarify the durability of ablation in arrhythmia control, clarify quality-of-life improvement, and identify patient populations in whom ablation may be expected to improve clinical outcomes. In this review, we summarize the major clinical trials involving ablation; discuss the strengths, weakness, and clinical implications of these trials; and highlight the knowledge gaps in our current understanding of AF ablation for future clinical studies.

Major adverse cardiovascular events and mortality after catheter ablation in Japanese patients with atrial fibrillation: The Fushimi AF Registry

BACKGROUND

The impact of catheter ablation (CA) on the long-term clinical outcomes in atrial fibrillation (AF) are unclear due to limited cohort investigations.

METHODS

The Fushimi AF Registry is a community-based prospective survey of patients with AF in Fushimi-ku, Kyoto, Japan. Of 4465 patients enrolled between March 2011 and July 2019, analyses were performed on 2639 patients (492 patients who underwent CA and 2147 patients who received standard rhythm- and/or rate-control drug therapy at baseline). We compared the baseline characteristics and the incidence of major adverse cardiovascular events (MACE: the composite of cardiovascular death, heart failure hospitalization, myocardial infarction, ischemic stroke or systemic embolism), and all-cause mortality during the follow-up using propensity score matching.

RESULTS

After entering 20 covariates in the current matching analysis, 342 patients who underwent CA and 342 matched patients who received drug therapy, with a median follow-up of 1865 days, were included. The patients who underwent CA were significantly associated with lower incidence of MACE (hazard ratio (HR) 0.56, 95% confidential interval (CI) 0.36-0.86; P = 0.0077), and all-cause mortality (HR 0.47, 95% CI 0.29-0.75; P = 0.0016).

CONCLUSION

CA was associated with lower incidences of MACE and all-cause mortality for patients with AF as compared with those who received drug therapy. The most common event of MACE in patients who underwent CA was heart failure hospitalization.

CLINICAL TRIAL REGISTRATION

URL: http://www.umin.ac.jp/ctr/index.htm UNIQUE IDENTIFIER: UMIN000005834.

Atrial Fibrillation (Part 2) - Catheter Ablation

More than 20 years since its initial use, catheter ablation has become a routinely performed procedure for the treatment of patients with atrial fibrillation (AF). Initially based on the electrical isolation of pulmonary veins in patients with paroxysmal AF, subsequent advances in the understanding of pathophysiology led to additional techniques not only to achieve better results, but also to treat patients with persistent forms of arrhythmia, as well as patients with structural heart disease and heart failure.

Cryoablation or Drug Therapy for Initial Treatment of Atrial Fibrillation

BACKGROUND

Guidelines recommend a trial of one or more antiarrhythmic drugs before catheter ablation is considered in patients with atrial fibrillation. However, first-line ablation may be more effective in maintaining sinus rhythm.

METHODS

We randomly assigned 303 patients with symptomatic, paroxysmal, untreated atrial fibrillation to undergo catheter ablation with a cryothermy balloon or to receive antiarrhythmic drug therapy for initial rhythm control. All the patients received an implantable cardiac monitoring device to detect atrial tachyarrhythmia. The follow-up period was 12 months. The primary end point was the first documented recurrence of any atrial tachyarrhythmia (atrial fibrillation, atrial flutter, or atrial tachycardia) between 91 and 365 days after catheter ablation or the initiation of an antiarrhythmic drug. The secondary end points included freedom from symptomatic arrhythmia, the atrial fibrillation burden, and quality of life.

RESULTS

At 1 year, a recurrence of atrial tachyarrhythmia had occurred in 66 of 154 patients (42.9%) assigned to undergo ablation and in 101 of 149 patients (67.8%) assigned to receive antiarrhythmic drugs (hazard ratio, 0.48; 95% confidence interval [CI], 0.35 to 0.66; P<0.001). Symptomatic atrial tachyarrhythmia had recurred in 11.0% of the patients who underwent ablation and in 26.2% of those who received antiarrhythmic drugs (hazard ratio, 0.39; 95% CI, 0.22 to 0.68). The median percentage of time in atrial fibrillation was 0% (interquartile range, 0 to 0.08) with ablation and 0.13% (interquartile range, 0 to 1.60) with antiarrhythmic drugs. Serious adverse events occurred in 5 patients (3.2%) who underwent ablation and in 6 patients (4.0%) who received antiarrhythmic drugs.

CONCLUSIONS

Among patients receiving initial treatment for symptomatic, paroxysmal atrial fibrillation, there was a significantly lower rate of atrial fibrillation recurrence with catheter cryoballoon ablation than with antiarrhythmic drug therapy, as assessed by continuous cardiac rhythm monitoring. (Funded by the Cardiac Arrhythmia Network of Canada and others; EARLY-AF ClinicalTrials.gov number, NCT02825979.).

A Novel Temperature-Controlled Radiofrequency Catheter Ablation System Used to Treat Patients With Paroxysmal Atrial Fibrillation

OBJECTIVES

DIAMOND-AF (DiamondTemp™ Ablation System for the Treatment of Paroxysmal Atrial Fibrillation) was a prospective, multicenter, noninferiority, randomized trial that compared the safety and effectiveness of the DTA system versus those of a force-sensing RF ablation system (control) for the treatment of patients with drug-refractory, recurrent, symptomatic paroxysmal atrial fibrillation (AF).

BACKGROUND

Irrigated radiofrequency (RF) ablation catheters lose tissue temperature acuity, which is vital in assessing lesion formation. DiamondTemp Ablation (DTA) was designed to re-establish accurate tissue temperature measurements during ablation.

METHODS

A total of 482 patients with paroxysmal AF were randomized (239 DTA, 243 control) to undergo pulmonary vein isolation and were followed up at 23 sites. Patients were screened for disease progression, cardiac characteristics, and prior interventions. Primary endpoints were effectiveness (freedom from atrial arrhythmia recurrence) and safety (composite of procedure- and device-related serious adverse events).

RESULTS

The primary safety event rate was 3.3% in the DTA group versus 6.6% in the control group (p < 0.001 vs. 6.5% noninferiority margin). Primary effectiveness was met in 79.1% of DTA subjects and 75.7% of control subjects (p < 0.001 vs. -12.5% noninferiority margin). Secondary endpoint analysis found that off-drug effectiveness favored DTA compared with the control (142 [59.4%] vs. 120 [49.4%], respectively; p = 0.03). Total RF time and individual RF ablation duration were significantly shorter with less saline infused through the DTA catheter (p < 0.001). Both arms saw clinically meaningful improvements in quality of life at 12 months.

CONCLUSIONS

Safety and efficacy of the DTA system proved noninferior to force-sensing RF ablation in a paroxysmal AF population. Efficiencies were observed using DTA with shorter total RF times, individual RF ablation durations, and less saline infusion. (DiamondTemp™ Ablation System for the Treatment of Paroxysmal Atrial Fibrillation; NCT03334630).

Transcatheter ablation for atrial fibrillation in patients with hypertrophic cardiomyopathy: Long-term results and clinical outcomes

INTRODUCTION

Radiofrequency transcatheter ablation (RFCA) for atrial fibrillation (AF) in patients with hypertrophic cardiomyopathy (HCM) has been proven feasible. However, the long-term results of RFCA and its impact on clinical course of HCM are unknown. The aim of this study was to analyse clinical outcomes and long-term efficacy of RFCA in a multicentre cohort of patients with HCM and concomitant AF.

METHODS

Patients with HCM and AF consecutively undergoing RFCA were included. Ablation failure was defined as recurrence of AF, atrial tachycardia, or flutter lasting more than 3 min and occurring after the blanking period.

RESULTS

Overall, 116 patients with symptomatic AF refractory to antiarrhythmic drugs were included. Over a median follow-up of 6.0 years (interquartile range: 3.0-8.9 years) recurrence rate after a single RFCA was 32.3 per 100 patient/years with 26% of patients free from AF relapses at 6-year follow-up. Among patients experiencing AF recurrence, 51 (66%) underwent at least one redo-procedure. The overall recurrence rate considering redo-procedures was 12.6 per 100 patients/years with 53% of patients free from AF relapses at 6 years. At last follow-up, with an average of 1.6 procedures, 67 (61%) patients were in sinus rhythm (SR). Patients remaining in SR showed better functional status compared with those experiencing arrhythmic recurrences (NYHA Class 1.6 ± 0.1 vs. 2.0 ± 0.1, p = .009).

CONCLUSIONS

RFCA of AF in HCM patients is an effective and safe strategy favoring long-term SR maintenance, reduction of atrial arrhythmic events, and improved functional status. However, most patients need repeat procedures and continuation of antiarrhythmic drugs.

High-power short-duration ablation of atrial fibrillation: A contemporary review

Catheter ablation using radiofrequency (RF) energy has been widely used to treat patients with atrial fibrillation (AF). The optimal levels of power and duration to increase the success rate while minimizing complications have not been fully established. Different centers continue to use various power protocols for catheter ablation of AF. Herein, we present a comprehensive review of the impact of power output on efficacy and safety of RF ablation for AF. High-power short-duration (HPSD) ablation can be performed safely with similar procedural efficacy as low-power long-duration ablation strategy. HPSD ablation has the potential to shorten procedural and RF times and create more durable and localized lesions.

Anesthetic Choice for Atrial Fibrillation Ablation: A National Anesthesia Clinical Outcomes Registry Analysis

OBJECTIVE

The authors evaluated the type of anesthesia administered in atrial fibrillation ablation, hypothesizing that monitored anesthesia care is used less frequently than general anesthesia.

DESIGN

A retrospective study.

SETTING

National Anesthesia Clinical Outcomes Registry data, which are multi-institutional from across the United States.

PARTICIPANTS

Adult patients who underwent elective atrial fibrillation ablation between 2013 and 2018.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

National Anesthesia Clinical Outcomes Registry data were evaluated, and covariates were selected a priori within multivariate models to assess for predictors of anesthetic type. A total of 54,321 patients underwent atrial fibrillation ablation; 3,251 (6.0%) received monitored anesthesia care. Patients who received monitored anesthesia care were more likely to be >80 years old (12.4% v 4.9%; p < 0.0001), female (36.1% v 34.3%; p < 0.0001), have American Society of Anesthesiologists physical status >III (17.28% v 10.48%; p < 0.0001), and reside in urban areas (62.23% v 53.37%; p < 0.0001). They received care in the Northeast (17.6% v 10.1%; p < 0.0001) at low-volume centers (median 224 v 284 procedures; p < 0.0001). Multivariate analysis revealed that each five-year increase in age, being female, and having an American Society of Anesthesiologists physical status >III resulted in a 7% (p < 0.0001), 9% (p = 0.032), and 200% (p < 0.0001) increased odds of receiving monitored anesthesia care, respectively. Requiring additional ablation of atria or of a second arrhythmia and residing outside the Northeast resulted in a decreased odds of monitored anesthesia care (adjusted odds ratio 0.24 [p=0.002] and < 0.5 [p < 0.03], respectively). For each 50 cases performed annually at a center, the odds decreased by 5% (p = 0.005).

CONCLUSIONS

General anesthesia is the most common type of anesthesia administered for atrial fibrillation ablation. The type of anesthesia administered, however, varies with patient, procedural, and hospital characteristics.

Symptom Under-Recognition of Atrial Fibrillation Patients in Consideration for Catheter Ablation: A Report From the KiCS-AF Registry

OBJECTIVES

This study sought to investigate whether symptom under-recognition is associated with the application of catheter ablation.

BACKGROUND

Atrial fibrillation (AF) symptom burden is frequently under-recognized and may affect the choice of treatment strategies.

METHODS

A total of 3,276 patients with AF consecutively registered in a Japanese multicenter database from 2012 to 2017 were analyzed. All patients underwent AF symptom burden assessment via the symptom and daily activities domain within the Atrial Fibrillation Effect on QualiTy-of-life (AFEQT) questionnaire. For the present analysis, 1,173 symptomatic patients (AFEQT score ≤80) with a clinical indication for catheter ablation were included. Under-recognition of symptom burden was defined as no subjective complaints checked by physicians despite self-reported AFEQT scores ≤80. Logistic regression analysis identified the predictors associated with receiving catheter ablation.

RESULTS

Of the 1,173 patients (age: 68 ± 12 years, men: 61%) analyzed, 459 underwent catheter ablation (ablation group); they had lower overall AFEQT scores (p < 0.01 for all domains) compared with the nonablation group. At the 1-year follow-up, greater improvement in the AFEQT scores was noted in the ablation group, even after adjusting for clinically relevant factors (+20.0 ± 1.2, +14.2 ± 0.9, respectively; p < 0.001). Notably, 306 (28%) patients met the criteria for symptom under-recognition, which was associated with the nonuse of catheter ablation during follow-up (odds ratio: 0.41; 95% confidence interval: 0.28 to 0.60; p < 0.001).

CONCLUSIONS

Under-recognition of AF symptom burden was frequently noted and was associated with less use of catheter ablation. Standardized recognition of symptoms using the application of validated questionnaires may facilitate outcome improvement.

Left atrial hypertension and the risk of early incident heart failure after atrial fibrillation ablation

INTRODUCTION

Elevated left atrial pressure (LAP) during catheter ablation of atrial fibrillation (AF) is associated with an increased risk of AF recurrence, but it is unknown if this correlates with heart failure (HF). The objective of the study was to determine if elevated LAP after AF ablation correlates with HF events.

METHODS

Prospective, single-center, cohort study measuring LAP and right atrial pressure (RAP) during AF ablation in 100 patients. The primary endpoint was clinical HF within 30 days of ablation. The secondary outcome was AF-free HF.

RESULTS

One hundred patients (63% male, mean age 64.5) were enrolled and 20% had clinical HF within 30 days. Bivariate correlates included mitral valve (MV) disease, persistent AF, class III antiarrhythmics, LAP, and recurrent AF. Multivariate analysis revealed class III antiarrhythmics were protective (odds ratio [OR]: 0.24 [0.1-0.5], p = .04), while MV disease (OR: 8.7 [3.3-23], p = .03) and loop diuretics (OR: 4.8 [2.6-9.1], p = .01) were hazardous. AF-free HF occurred in 9% of patients and correlated with higher LAP and RAP, and chronic kidney disease.

CONCLUSION

Patients with HF after AF ablation had higher LAP. MV disease, diuretic use, and class III antiarrhythmics also correlated to HF. These present opportunities to target future interventions to reduce a common complication of AF ablation.

Prospective Randomized Evaluation of High Power During CLOSE-Guided Pulmonary Vein Isolation: The POWER-AF Study

BACKGROUND

CLOSE-guided atrial fibrillation (AF) ablation is based on contiguous (intertag distance ≤6 mm), optimized (Ablation Index >550 anteriorly and >400 posteriorly) point-by-point radiofrequency lesions. The optimal radiofrequency power remains unknown.

METHODS

The POWER-AF study is a prospective, randomized controlled monocentric study including patients with paroxysmal AF, planned for first CLOSE-guided pulmonary vein isolation using a contact force radiofrequency catheter (Thermocool SmartTouch, Biosense Webster, Inc, Irvine, CA). A total of 100 patients were randomized into 2 groups (1:1). The control group received AF ablation using the standard CLOSE protocol (35 W), whereas in the experimental group, pulmonary vein isolation was performed using high power (45 W). Endoscopic evaluation was performed in patients with intraesophageal temperature rise >38.5 °C.

RESULTS

The resulting sample size was 96 (48+48) patients. In the high power group, shorter procedure time (80 versus 102 minutes, P<0.001), shorter total radiofrequency application time (16 versus 26 minutes, P<0.001), and radiofrequency time per application (26 versus 37 s anteriorly, P<0.001 and 13 versus 17 s posteriorly, P<0.001) were observed. Endoscopic evaluation (performed in 19/48 versus 25/48 patients respectively, P=0.31) showed an ulcerative perforation in a high power group patient (treated by endoscopic stenting and normalization after ≈4 months) and a superficial ulcerative lesion in a control group patient (conservative treatment). Both occurred following excessive Ablation Index applications (up to 460 and 480, respectively) with excessive contact force (30 g on average, with peaks up to 50 g). Six-months AF recurrence was not significantly different (10% in high power versus 8% in control, P=0.74).

CONCLUSIONS

This randomized controlled study shows that a 45 W radiofrequency power CLOSE protocol in patients with paroxysmal AF significantly increases the global procedural efficiency with similar midterm efficacy. However, our study showed a narrower safety margin and a limited increased efficiency at the posterior wall using high power. This advocates against the use of high power in the region neighboring the esophagus.

Left atrio-oesophageal fistula after atrial fibrillation ablation

We report a case of a 68-year-old woman who presented with atypical chest pain and fluctuating neurological symptoms 4 weeks after cryoballoon ablation procedure for atrial fibrillation. Brain imaging showed multiple embolic infarcts, while the chest imaging revealed an abnormal connection between the posterior wall of the left atrium and the oesophagus. Based on her clinical presentation and the imaging findings, a diagnosis of left atrio-oesophageal fistula (AOF) was established. AOF carries a high mortality rate unless an urgent surgical repair is performed. Oesophageal instrumentation for an echocardiogram or endoscopy should be avoided as it can result in massive air embolus, causing stroke or death.

Positive Clinical Benefit on Patient Care, Quality of Life, and Symptoms After Contact Force-Guided Radiofrequency Ablation in Persistent Atrial Fibrillation: Analyses From the PRECEPT Prospective Multicenter Study

BACKGROUND

There is limited evidence on the long-term clinical benefits of catheter ablation in patients with persistent atrial fibrillation.

METHODS

PRECEPT was a prospective, multicenter, single-arm Food and Drug Administration-regulated investigational device exemption clinical study. Patients were followed up to 15 months after ablation. Outcomes included use of antiarrhythmic drugs, rate of cardioversions and cardiovascular hospitalization, Atrial Fibrillation Effect on Quality-of-Life score, and Canadian Cardiovascular Society Severity of Atrial Fibrillation score.

RESULTS

A total of 333 enrolled persistent atrial fibrillation patients underwent ablation. The cardioversion rate decreased by 83% at the 9- to 15-month follow-up. Antiarrhythmic drug utilization decreased by 69% at 12 to 15 months post-ablation. The Kaplan-Meier estimate of freedom from cardiovascular hospitalization was 84.2% (95% CI, 80.2%-88.2%) at 15 months. Consistent improvements in mean Atrial Fibrillation Effect on Quality-of-Life composite (+50.0) were seen at 6 months, sustained at 15 months, and exceeded the minimum clinically important difference. Improvements in Atrial Fibrillation Effect on Quality-of-Life scores were significantly better among participants without documented atrial arrhythmia recurrences. By Canadian Cardiovascular Society Severity of Atrial Fibrillation symptom classification, >80% of patients were asymptomatic (class 0) at 15 months post-ablation compared with only 0.7% at baseline.

CONCLUSIONS

Contact force-guided radiofrequency ablation of persistent atrial fibrillation was associated with a significant decrease in antiarrhythmic drug use, cardioversion rate, and hospitalization. Clinically meaningful improvements in quality of life were observed in all patients. The majority of the patients (>80%) were asymptomatic at 15 months post-ablation. The positive clinical impact of improved quality of life and reduced health care utilization may help with shared decision-making in persistent atrial fibrillation treatment. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02817776.

Association of the left common ostium with clinical outcome after pulmonary vein isolation in atrial fibrillation

Introduction

Electrical pulmonary vein isolation (PVI) is used for the invasive treatment of atrial fibrillation (AF). However, despite the procedure’s technical evolution, the rate of AF recurrence due to electrical reconnection of the PVs is high. The aims of this study was to assess the influence of left common pulmonary venous ostium (LCO) on clinical outcomes following PVI.

Methods

Retrospective cohort of 254 patients who underwent the first procedure of PVI from the years 2013–2018 was assessed. Patients with persistent AF of long duration and extra-pulmonary focus associated with triggers for arrhythmia were excluded. Patients were stratified into two groups according to the presence of a LCO and received follow up for atrial tachyarrhythmia-free survival. The mean follow-up period was 28 ± 1.73 months.

Results

The majority were men (68.5%), with a mean age of 54 ± 12 years. With respect to the atrial anatomy, LCO occurred in 23.6% of cases after pulmonary venous angiotomography. The arrhythmia-free survival rate was 79.5% in the follow-up period. The Cox regression model was utilized and the adjusted hazard ratio for LCO was 0.36 (95% CI 0.15–0.87; p = 0.02) in terms of age, body mass index, left atrium diameter, bi-directional blocking of the cavotricuspid isthmus, persistent AF, left ventricular ejection fraction adjusted model.

Conclusion

Anatomic abnormality with the presence of the LCO is present in a quarter of patients undergoing AF ablation, which is associated with a lower rate of arrhythmia recurrence in our population.

•

Pulmonary vein isolation is used for the invasive treatment of atrial fibrillation.

•

The majority of arrhythmias triggers have their origins in the anatomic abnormality.

•

Pulmonary vein isolation using radiofrequency ablation.

Left atrial scar identification and quantification in sinus rhythm and atrial fibrillation

Identification and quantification of low voltage areas (LVA) in atrial fibrillation (AF), identified by their bipolar voltages (BiV) via electro-anatomical voltage mapping is an area of interest to prognosis of AF free burden. LVAs have been linked to diseased left atrial (LA) tissue which results in pro-fibrillatory potentials. These LVAs are dominantly found within the pulmonary veins, however, as the disease progresses other areas of the LA show low voltage. The scar burden of the LA is linked to recurrence of the arrhythmia and can be a target of further modification. This burden is classically assessed once sinus rhythm (SR) is attained, but this is susceptible to operator variability with overestimated dense LA scar (<0.2 mV) and underestimated diseased LA tissue (<0.5 mV). The novel automated voltage histogram analysis (VHA) tool may increase accuracy, however, is yet to be fully validated. A recent study indicates that LVAs can be assessed just as reliably in AF as SR, but BiV is lower with linear correlation to SR values (0.24-0.5 mV respectively). In this paper, we review current data as well as review current methods of identifying, quantifying, and grading LA scar. We also compared AF vs SR voltages of a patient undergoing catheter ablation in our site using our VHA tool to compare the results. In keeping with the cited papers, we found lower voltages in our patient measured in AF. This area warrants further study to assess correlation in more patients, with view to developing prognostic and therapeutic grading systems.

A novel and simple scoring system for assessing the indication for catheter ablation in patients with atrial fibrillation: The HEAL-AF Score

INTRODUCTION

A scoring system to determine indications for catheter ablation (CA) in atrial fibrillation (AF) is desired.

METHODS AND RESULTS

Among 2898 consecutive patients with AF, CA was performed in 938 (32.4%). A new HEAL-AF score has been developed by six variables, all of which were independently associated with CA by multivariate analysis and for each 1 point was assigned: heart failure ≥ NYHA II, elderly patients (age ≥75 years), asymptomatic AF, long-standing persistent AF, atrial dilation (left atrial diameter ≥ 50 mm), and female sex. Low HEAL-AF score was associated with high incidence of CA performance (52.0% for 0, 36.5% for 1, 15.1% for 2, and 5.6% for ≥ 3) and the predictive capability of this score by AUC of ROC curve was 0.720 (95% CI 0.701-0.739, P < .001). The rates of freedom from AF/AT recurrence were 73.2% in HEAL-AF score 0, 71.0% in 1, 60.0% in 2, and 50.0% in ≥ 3 (log-rank test, P = .004). HEAL-AF score 2 and ≥ 3 were significantly associated with recurrence of atrial tachyarrhythmia as compared with HEAL-AF 0 (HR 1.755, P = .002, and HR 2.211, P = .007, respectively).

CONCLUSIONS

A new HEAL-AF score was associated with patient indication for and the recurrence of atrial tachyarrhythmia after CA in patients with AF. Prescription of CA should be considered carefully in AF patients with HEAL-AF score of 2 and ≥ 3.

Advances in the management of atrial fibrillation with a special focus on non-pharmacological approaches to prevent thromboembolism: a review of current recommendations

Atrial fibrillation (AFIB) is the most common heart rhythm abnormality and is associated with significant morbidity and mortality. While the treatment of AFIB involves strategies of rate with or without rhythm control, it is also essential to strategize appropriate therapies to prevent thromboembolic complications arising from AFIB. Previously, anticoagulation was the main treatment option which exposed patients to higher than usual risk of bleeding. However, with the advent of new technology, novel therapeutic options aimed at surgical or percutaneous exclusion or occlusion of the left atrial appendage in preventing thromboembolic complications from AFIB have evolved. This review evaluates recent advances and therapeutic options in treating AFIB with a special focus on both surgical and percutaneous interventions which can reduce and/or eliminate thromboembolic complications of AFIB.

A deep learning model to predict recurrence of atrial fibrillation after pulmonary vein isolation

Background and Objectives

The efficacy of radiofrequency catheter ablation (RFCA) in atrial fibrillation (AF) is well established. The standard approach to RFCA in AF is pulmonary vein isolation (PVI). However, a large proportion of patients experiences recurrence of atrial tachyarrhythmia. The purpose of this study is to find out whether the AI model can assess AF recurrence in patients who underwent PVI.

Materials and methods

This study was a retrospective cohort study that enrolled consecutive patients who underwent catheter ablation for symptomatic, drug-refractory AF and PVI. We developed an AI algorithm to predict recurrence of AF after PVI using patient demographics and three-dimensional (3D) reconstructed left atrium (LA) images.

Results

We included 527 consecutive patients in the study. The overall mean LA diameter was 42.0 ± 6.8 mm, and the mean LA volume calculated using 3D reconstructed images was 151.1 ± 46.7 ml. During the follow-up period, atrial tachyarrhythmia recurred in 158 patients. The area under the curve (AUC) of the AI model based on a convolutional neural network (including 3D reconstruction images) was 0.61 (95% confidence interval [CI] 0.53–0.74) using the test dataset. The total test accuracy was 66.3% (57.0–75.6), and the sensitivity was 53.3% (34.8–71.9). The specificity was 73.2% (51.8–75.0), and the F1 score was 52.5% 34.5–66.7).

Conclusion

In this study, we developed an AI algorithm to predict recurrence of AF after catheter ablation of PVI using individual reconstructed LA images. This AI model was unable to predict recurrence of AF overwhelmingly; therefore, further large-scale study is needed.

Meta-Analysis of Atrial Fibrillation and Outcomes in Patients With Heart Failure and Preserved Ejection Fraction

BACKGROUND

Atrial fibrillation (AF) is common in heart failure with preserved ejection fraction (HFpEF); However, the prognostic impact of AF on HFpEF patients has not been fully elucidated.

METHODS

A literature search of the PubMed and EMBASE databases on literature published through April 2019 was undertaken. Combined hazard ratio (HR) estimates and 95% confidence intervals (CIs) were calculated using fixed-effects or random-effects models, depending on the heterogeneity. Subgroup analyses, sensitivity analysis and meta-regression analyses were also performed.

RESULTS

Fourteen (14) eligible studies with 1,948,923 patients with HFpEF were included in the analysis. Atrial fibrillation was associated with an 11% increased risk of all-cause mortality in patients with HFpEF (HR 1.11, 95% CI 1.09-1.12). Sensitivity analysis confirmed the stability of the results. The stratification of studies by controlled or uncontrolled confounding factors affected the final estimate (confounder-controlled HR 1.21, 95% CI 1.12-1.30; confounder-uncontrolled HR 1.13, 95% CI 0.96-1.31). In addition, AF was an independent predictor of hospitalisation for heart failure (HR 1.32, 95% CI 1.15-1.52), cardiovascular death (HR 1.38, 95% CI 1.01-1.89) and stroke (HR 1.87, 95% CI 1.54-2.27).

CONCLUSIONS

Atrial fibrillation was associated with worse clinical outcomes in patients with HFpEF. Further investigation is required to see whether AF is the primary offender in these patients or merely a bystander to worse diastolic function.

Renal Sympathetic Denervation as Upstream Therapy During Atrial Fibrillation Ablation: Pilot HFIB Studies and Meta-Analysis

OBJECTIVES

This study sought to determine the impact of adjunctive renal sympathetic denervation to catheter ablation in patients with atrial fibrillation (AF) and history of hypertension.

BACKGROUND

There are limited data regarding the impact of upstream adjunctive renal sympathetic denervation (RSDN) to pulmonary vein isolation (PVI) in patients with symptomatic atrial fibrillation (AF) and hypertension.

METHODS

The data for this study were obtained from 2 prospective randomized pilot studies, the HFIB (Adjunctive Renal Denervation to Modify Hypertension and Sympathetic tone as Upstream Therapy in the Treatment of Atrial Fibrillation)-1 (n = 30) and HFIB (Adjunctive Renal Denervation to Modify Hypertension and Sympathetic tone as Upstream Therapy in the Treatment of Atrial Fibrillation)-2 (n = 50) studies, and we performed a meta-analysis including all published studies comparing RSDN+PVI versus PVI alone up to January 25, 2020, in patients with AF and hypertension.

RESULTS

At 24 months, AF recurrence occurred in 53% and 38% in the PVI and PVI+RSDN groups (p = 0.43) in the HFIB-1 study, respectively, and 27% and 25% in the PVI and PVI+RSDN groups (p = 0.80) in the HFIB-2 study, respectively. When combined in a meta-analysis including 6 studies (n = 725), adjunctive RSDN significantly decreased the risk of AF recurrence (risk ratio [RR]: 0.68; 95% confidence interval [CI]: 0.55 to 0.83; p = 0.0002; I² = 0%) when compared with PVI. Six renal artery complications occurred in the HFIB-1 study and none occurred in the HFIB-2 study with RSDN. However, in the meta-analysis, there were no significant differences in overall complications between both groups (RR: 1.43; 95% CI: 0.63 to 3.22; p = 0.40; I² = 7%). When compared with baseline, RDSN significantly reduced the systolic blood pressure (-12.1 mm Hg; 95% CI: -20.9 to -3.3 mm Hg; p < 0.007; I² = 99%) and diastolic blood pressure (-5.60 mm Hg; 95% CI: -10.05 to -1.10 mm Hg; p = 0.01; I² = 98%) on follow-up.

CONCLUSIONS

The pilot HFIB-1 and HFIB-2 studies did not demonstrate a benefit with RSDN as an adjunctive upstream therapy during PVI. However, in the meta-analysis, adjunctive RSDN to PVI appears to be safe, and improves clinical outcomes in AF patients with a history of hypertension.

Changes in quality of life, cognition and functional status following catheter ablation of atrial fibrillation

OBJECTIVE

To investigate changes in quality of life (QoL), cognition and functional status according to arrhythmia recurrence after atrial fibrillation (AF) ablation.

METHODS

We compared QoL, cognition and functional status in patients with recurrent atrial tachycardia (AT)/AF versus those without recurrent AT/AF in the AXAFA-AFNET 5 clinical trial. We also sought to identify factors associated with improvement in QoL and functional status following AF ablation by overall change scores with and without analysis of covariance (ANCOVA).

RESULTS

Among 518 patients who underwent AF ablation, 154 (29.7%) experienced recurrent AT/AF at 3 months. Patients with recurrent AT/AF had higher mean CHA₂DS₂-VASc scores (2.8 vs 2.3, p<0.001) and more persistent forms of AF (51 vs 39%, p=0.012). Median changes in the SF-12 physical (3 (25th, 75th: -1, 8) vs 1 (-5, 8), p=0.026) and mental scores (2 (-3, 9) vs 0 (-4, 5), p=0.004), EQ-5D (0 (0,2) vs 0 (-0.1, 0.1), p=0.027) and Karnofsky functional status scores (10 (0, 10) vs 0 (0, 10), p=0.001) were more favourable in patients without recurrent AT/AF. In the overall cohort, the proportion with at least mild cognitive impairment (Montreal Cognitive Assessment <26) declined from 30.3% (n=157) at baseline to 21.8% (n=113) at follow-up. ANCOVA identified greater improvement in Karnofsky functional status (p<0.001) but not SF-12 physical (p=0.238) or mental scores (p=0.065) in those without recurrent AT/AF compared with patients with recurrent AT/AF.

CONCLUSIONS

Patients without recurrent AT/AF appear to experience greater improvement in functional status but similar QoL as those with recurrent AT/AF after AF ablation.

Catheter ablation for atrial fibrillation: current indications and evolving technologies

Catheter ablation for atrial fibrillation (AF) has emerged as an important rhythm-control strategy and is by far the most common cardiac ablation procedure performed worldwide. Current guidelines recommend the procedure in symptomatic patients with paroxysmal or persistent AF who are refractory or intolerant to antiarrhythmic drugs. The procedure might also be considered as a first-line approach in selected asymptomatic patients. Data from large registries indicate that AF ablation might reduce mortality and the risk of heart failure and stroke, but evidence from randomized controlled trials is mixed. Pulmonary vein isolation using point-by-point radiofrequency or with the cryoballoon remains the cornerstone technique in AF ablation. Additional atrial ablation can be performed in patients with persistent AF, but its benefits are largely unproven. Technological advances in the past decade have focused on achieving durable vein isolation, reducing procedure duration and improving safety. Numerous exciting new technologies are in various stages of development. In this Review, we discuss the relevant data to support the recommended and evolving indications for catheter ablation of AF, describe the different ablation techniques, and highlight the latest advances in technology that aim to improve its safety and efficacy. We also discuss lifestyle modification strategies to improve ablation outcomes.

Combined epicardial and endocardial ablation for atrial fibrillation: Best practices and guide to hybrid convergent procedures

The absence of strategies to consistently and effectively address nonparoxysmal atrial fibrillation by nonpharmacological interventions has represented a long-standing treatment gap. A combined epicardial/endocardial ablation strategy, the hybrid Convergent procedure, was developed in response to this clinical need. A subxiphoid incision is used to access the pericardial space facilitating an epicardial ablation directed at isolation of the posterior wall of the left atrium. This is followed by an endocardial ablation to complete isolation of the pulmonary veins and for additional ablation as needed. Experience gained with the hybrid Convergent procedure during the last decade has led to the development and adoption of strategies to optimize the technique and mitigate risks. Additionally, a surgical and electrophysiology "team" approach including comprehensive training is believed critical to successfully develop the hybrid Convergent program. A recently completed randomized clinical trial indicated that this ablation strategy is superior to an endocardial-only approach for patients with persistent atrial fibrillation. In this review, we propose and describe best practice guidelines for hybrid Convergent ablation on the basis of a combination of published data, author consensus, and expert opinion. A summary of clinical outcomes, emerging evidence, and future perspectives is also given.

High Cerebrovascular Thromboembolic Event Rate Long after Unsuccessful Catheter Ablation for Atrial Fibrillation

Background

Although catheter ablation (CA) is an accepted therapeutic option for atrial fibrillation (AF), data is lacking concerning the long-term thromboembolic event (TE) and mortality rate of patients after unsuccessful CA for AF.

Objective

The aim of the current study was to detect the long-term TE and mortality rate of patients with successful CA (group A) of AF and compared those with unsuccessful ablation (group B).

Methods

Following a 4-years of follow-up (FU) 330 patients were included into the groupA, and 105 patients into the group B. Primary outcome was defined as all stroke/TIA occurrence. Secondary outcome was considered as all-cause mortality and stroke - and TIA only occurrence.

Results

Seventeen patients developed a stroke/TIA during a median of 5.8 [5.1-7.3] years of FU. In the group A 8 (2.4%) patients developed a stroke/TIA during a FU of 2037 person-years (incidence rate 3.92 per 1000 person-years), compared to 9 patients in the group B during a FU of 726 person-years (incidence rate 12.4 per 1000 person-years). The crude HR for primary outcome was 2.84 (95% CI 1.078-7.48) in the group B compared with the group A. Cumulative TIA-alone incidence (3.97, CI 1.10-14.34, p=0.035) and the annualized TIA-alone incidence rate was significantly higher in the group B. (p=0.029). Neither the mortality rate nor the incidence rate of stroke-alone differed significantly among the groups.

Conclusions

The risk of all stroke/TIA and TIA-alone is higher among patients after unsuccessful CA of AF compared to those after successful ablation.